Electroencephalogram measurement system, electroencephalogram measurement method, and program thereof

Abstract

An exemplary electroencephalogram measurement system includes: a frequency analysis section for, analyzing a frequency power of the electroencephalogram signal of a user with respect to each set of a reference electrode and a measurement electrode; an insufficient electrode determination section for, through comparison of the analyzed frequency power against a first threshold value, distinguishing whether a state of attachment of each electrode is sufficient or not; and an insufficiency cause estimation section for determining the number of insufficient electrodes distinguished as insufficiently worn, determining a position at which each insufficient electrode is in contact with the user, and estimating a cause for the insufficient state of attachment of the insufficient electrode or electrodes that corresponds to the determined number of insufficient electrodes and position of each insufficient electrode by referring to insufficiency pattern data.

Description

[0001]This is a continuation of International Application No. PCT / JP2011 / 003333, with an international filing date of Jun. 13, 2011, which claims priority of Japanese Patent Application No. 2010-134766, filed on Jun. 14, 2010, the contents of which are hereby incorporated by reference.BACKGROUND[0002]1. Technical Field[0003]The present disclosure relates to a system for measuring an electroencephalogram of a user who wears on his or her head a housing having electrodes provided thereon. Specifically, the present disclosure relates to an electroencephalogram measurement system for determining states of attachment of electrodes, and estimating an insufficiency cause in accordance with the position of any insufficient electrode.[0004]2. Description of the Related Art[0005]Conventionally, as a method of measuring an electroencephalogram (Electroencephalogram: EEG), a method which records changes in the potentials of two points on the scalp (potentials of a reference electrode and an ele...

AI Technical Summary

Benefits of technology

The patent describes a technique to determine which electrodes in an electroencephalogram measurement device are not working properly and to estimate the cause of the insufficiency. This helps to easily achieve stable electroencephalogram measurements in a daily-life environment. The technique involves analyzing the frequency power of the electroencephalogram signal measured by the electrodes and comparing it to a predetermined threshold value to determine if the electrodes are insufficiently attached to the user. The system can also determine the position at which each insufficient electrode comes in contact with the user and estimate the cause of the insufficiency based on the data stored in the system. This technique helps to improve the accuracy and reliability of electroencephalogram measurements.

Problems solved by technology

For the electrode attachment, about several minutes is required for each electrode, which is a relatively long time.

However, in such manners of use, which require lead wires or a special cap to be attached with the help of a specialist, it is difficult for a user in a daily-life environment to wear the electrodes by himself or herself, have their electroencephalogram measured, and have the resultant electroencephalogram used for an electroencephalogram interface or the like.

However, use of dry electrodes presents a problem in wearing stability.

This results in the electrode position changing even though contact with the skin may be maintained (“electrode shifting”), or the electrode becoming lifted off the skin to create a space between the skin and the electrode, thus disabling electroencephalogram measurement (“electrode disengagement”).

If an electrode disengagement occurs, electroencephalogram measurement will be so affected that it is made impossible.

Since the user will not always be in a resting state but will undergo various motions in a daily-life environment, insufficiencies concerning electrode contact, such as electrode shifting and electrode disengagement, are likely to occur.

An insufficient electrode is an electrode in a poor state of attachment, i.e., an electrode which is not in a good state of attachment with the skin, such that an electroencephalogram cannot be properly measured.

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